Apparatus for cooling a roll on a roll stand

ABSTRACT

The invention concerns an apparatus ( 1 ) for cooling a roll ( 2 ) in a roll stand and provided with at least one spray beam ( 3 ) supplied with a cooling medium, especially water, with spray nozzles ( 4 ) for spraying cooling medium onto the surface of the roll ( 2 ), and that extends generally parallel to a spray beam axis ( 5 ) extending parallel to the roll axis ( 6 ). In order to be able to adjust the spray beam for changed roll diameters, the invention provides that the spray beam ( 3 ) is mounted directly or indirectly on a lever ( 7 ) that can pivot around a rotation axis ( 8 ) that is parallel to the roll axis ( 6 ), and the spray beam axis ( 5 ) and the rotation axis ( 8 ) are spaced from each other.

The invention concerns an apparatus for cooling a roll in a roll stand with at least one spray beam supplied with a cooling medium, particularly with water, that has spray nozzles for spraying cooling medium onto the surface of the roll, and that extends generally parallel to a spray beam axis extending parallel to the roll axis.

A cooling apparatus of this type has been described in the prior art. EP 0 374 538 [U.S. Pat. No. 4,912,955] discloses a cooling apparatus designed for spraying water onto the rolls of the roll stand, for which a spray beam is used. There, the problem is recognized that the optimal position of the spray beam changes depending on the rolls used, so that such is designed adjustable. The spray beam is suspended such that it can be moved horizontally and vertically in such a way that the roll can be cooled optimally.

A similar solution is shown in EP 0 542 640 [U.S. Pat. No. 5,212,975]. Here too, a spray beam is provided for cooling a roll. It can be rotated around the longitudinal axis of the spray beam to adjust the position of the spray beam. In this way, optimal spraying of the roll is achieved.

Additional solutions of cooling systems are described in EP 1 399 276 [U.S. Pat. No. 7,266,698], in EP 1 142 652 [U.S. Pat. No. 6,450,000], in DE 34 19 261 [U.S. Pat. No. 4,750,343], in DE 94 18 359, in DE 195 03 544 and in U.S. Pat. No. 5,460,023.

All these solutions have in common that either a complex mechanism must be used to achieve spray beam adjustment that is stable, reliable and precise in difficult rolling-mill conditions, which is associated with corresponding costs, or that the adjustment possibilities of the spray beam are not sufficient to, particularly for different roll diameters, always be able to obtain the optimal spray beam positioning and alignment.

Therefore, the object of present invention is to develop a cooling apparatus of the type described above further in such a way that with a simple and stable design that can be realized in a cost-effective manner, an optimal adjustment of the spray beam of the cooling apparatus is made possible. Furthermore, it must ensure in particular that after a change of rolls and the associated changed roll diameter and/or change of the position of the roll, the optimal spray beam position and alignment can always be selected, in order to achieve an optimal cooling result.

This object is attained by the invention in that the spray beam is mounted directly or indirectly on a lever that can pivot about a rotation axis extending parallel to the roll axis and the spray beam axis and the rotation axis are spaced from each other.

Accordingly, the spray beam can be moved in a straight line in two spatial directions by a pivoting motion of the lever, and thus be adjusted relative to the roll to be cooled.

Thus, the lever is preferably connected to the actuator at a location offset from the rotation axis. Preferably, the lever has two arms, the spray beam being mounted directly or indirectly on the first arm and the actuator being mounted on the second arm.

The adjustment possibilities of the spray beam are increased further by the following provisions: The spray beam can be mounted indirectly on the main lever by an intermediate lever that is mounted such that it can be pivoted around a rotation axis extending parallel to the roll axis. For pivoting the intermediate lever around its rotation axis, an additional actuator can be mounted. The additional actuator is preferably operatively connected between the second arm and the intermediate lever. The spray beam can be fixedly connected with the intermediate lever. The rotation axis of the intermediate lever is preferably located between the spray beam and the point of application of the additional actuator on the intermediate lever.

The actuators are preferably designed to create defined displacement paths. Preferably, but not necessarily, the actuators are hydraulic piston-cylinder systems.

As a result of the proposed solution it is possible to achieve evened cooling of a roll, independent of roll diameter.

In particular, with it, the same coverage of the spray of the individual spray nozzles can be maintained, so that the same cooling effect is always attainable, specifically for different roll diameters.

In the proposed solution, the spacings between nozzle and roll or roll and coverage of the cooling medium spray are always held constant as the result of simple and optimal readjustment of the spray beam for various rolls or roll diameters.

In principle, hydraulic, pneumatic or electrically operated actuators are usable as actuators, eccentric cam disks or articulated joints also being usable. There also exists the possibility of using the proposed solution when parameters of the cooling medium are changed in order to influence the cooling effect.

Thus, with the proposed embodiment, the same spacing of the spray nozzles from the roll can always be selected and the surface impinged upon by the spray nozzle can be held constant. This way, the impact pressure and point of impact of the cooling medium is held constant on the roll surface.

The spray beam can also be pivoted to achieve a vertical change of the point of impact and thus a change in the cooling effect. Pivoting of the spray beam for a targeted change of the coverage of the spray is also possible.

The drawings show embodiments of the invention. Therein:

FIG. 1 is a side view of an apparatus for cooling a roll of a roll stand, using a roll with a first diameter,

FIG. 2 is a side view of the same apparatus using a roll with a second, smaller diameter,

FIG. 3 is a partial perspective cross-sectional view of the cooling apparatus as in FIG. 1 or FIG. 2, for the upper roll of the roll stand, as well as an alternatively designed cooling apparatus for a lower roll,

FIG. 4 is a perspective view of the cooling apparatus of FIG. 3 for the lower roll.

FIG. 1 schematically illustrates an apparatus 1 for cooling a roll 2 of a roll stand (not shown). An important component of the cooling apparatus is a spray beam 3 that is supplied by a water line 15 with water sprayed in a manner known per se by nozzles 4 and onto the surface of the roll 2. The spray beam 3 is tubular and has an axis 5 extending parallel to a roll axis 6.

In order to be able to adapt the spray beam 3 optimally to various diameters of roll or rolls 2, the spray beam is not stationary, but is movable. To this end, a lever 7 is provided that is mounted so that it can be pivoted around a fixed rotation axis 8. The lever 7 has two arms 10 and 11. The spray beam 3 is mounted indirectly via an intermediate lever 12 at the outer end of the first arm 10. An actuator 9 of the linear type engages the second arm 11. The actuator 9 is pivoted at its other end 16 at a stationary point.

If the actuator 9 is operated, the lever 7 is pivoted about its rotation axis 8, so that the end of the first arm 10 moves the spray beam 3 around the rotation axis 8 in a circular arc and readjusts its position. Accordingly, the spacing of the spray nozzles 4 from the roll surface is changed. This effect can be utilized in order to adjust the spray beam 3 for changing roll diameters and to thus always maintain the same (optimal) cooling conditions.

In addition, the spray beam 3 is also located in such a way that its position can also be adjusted (especially rotated around the spray beam axis 5). To this end, the already mentioned intermediate level 12 is provided. The intermediate lever 12 is used for the indirect mounting of the spray beam 3 at the end of the first arm 10. The intermediate lever 12 is mounted on the end of the first arm 10 of lever 7, i.e. it can pivot around a rotation axis 13 relative to the first arm 10. The pivoting motion is controlled by a second actuator 14 that has one pivoted on the intermediate lever 12 and another end pivoted on the second arm 11 of the lever 7.

By joint action of the two actuators 9 and 14, the spray beam 3 consequently can be optimally adjusted with respect to its horizontal and vertical position relative to roll 2, rotation of the spray beam 3 around its spray beam axis 5 being superimposed on this motion.

A comparison of FIGS. 1 and 2 shows how such a readjustment takes place when it is important after a change of rolls to place the spray beam 3 optimally in position. In FIG. 1, a roll 3 is used that has a larger diameter than the roll 2 seen in FIG. 2.

Accordingly, in FIG. 2 the lever 7 was pivoted through an angle α by the actuator 9. As a result of a readjustment motion of the second actuator 14, a correction of the vertical position of the spray beam can be made.

In FIG. 3, a roll stand is shown which an upper roll 2 and a lower roll 2′ that works together with it is indicated, provided with respective cooling apparatus 1 and 1′.

As can be seen, the two rolls 2 and 2′, are provided with different cooling apparatuses 1 and 1′. Apparatus 1 is used for the upper roll 2, as described in FIGS. 1 and 2.

For the lower roll 2′, the cooling apparatus 1′ of simpler design is used, as illustrated in somewhat more detail in FIG. 4.

According to it, the cooling apparatus 1′ is also provided with a spray beam 3′ with spray nozzles 4′, but here, however, the spray beam 3′ is fixed directly to a lever 7′. The actuator 9′ engages the lever 7′ in such a way that this lever 7′ including the respective spray beam 3′ can be pivoted toward the roll 2′ or away from it.

In both solutions that were described—i.e. for apparatus 1 and apparatus 1′—the same principle applies, namely, that the spray beam 3 or 3′ is mounted directly or indirectly on the lever 7 or 7′. Here, the lever 7 or 7′, is mounted so that it can pivot around a rotation axis 8 that is parallel to the roll axis 6. The spray beam axis 5 and the rotation axis 8 are spaced from each other.

Among other things, the outcome of the cooling is dependent on the cooling medium, its pressure, its temperature, its quantity, the type of nozzle and orientation relative to the spray beam and of course, also from the distance between the nozzle and the roll or drum that is to be cooled, as well as the temperature of the roll.

Accordingly, a different type of nozzle or a different coverage can influence the cooling effect extending over the width of the roll.

REFERENCE NUMBERS

-   1 Apparatus -   1′ Apparatus -   2 Roll -   2′ Roll -   3 Spray beam -   3′ Spray beam -   4 Spray nozzle -   4′ Spray nozzle -   5 Spray beam axis -   6 Roll axis -   7 Lever -   7′ Lever -   8 Rotation axis -   9 Actuator -   9′ Actuator -   10 First arm -   11 Second arm -   12 Intermediate lever -   13 Rotation axis -   14 Actuator -   15 Water line -   16 End of actuator -   α Angle 

1. An apparatus for cooling a roll in a roll frame, comprising at least one spray beam supplied with a cooling medium that has spray nozzles for spraying the cooling medium onto the surface of the roll, and that extends generally parallel to a spray beam axis extending parallel to the roll axis, wherein the spray beam is mounted directly or indirectly on a lever that can pivot about a rotation axis extending parallel to the roll axis and the spray beam axis and the rotation axis are spaced from each other.
 2. The apparatus according to claim 1, wherein the lever is connected with an actuator at a location offset from the rotation axis.
 3. The apparatus according to claim 2, wherein the lever has two arms, the spray beam being mounted directly or indirectly on the first arm and whereby the actuator being connected to the second arm.
 4. The apparatus according to claim 1, wherein the spray beam is mounted on the lever indirectly via an intermediate lever, the intermediate lever being mounted so that it can be pivoted on the lever at a rotation axis extending parallel to the roll axis.
 5. The apparatus according to claim 4, wherein an additional actuator is provided for pivoting the intermediate lever around its rotation axis.
 6. The apparatus according to claim 5, wherein the additional actuator is operative connected between the second arm and the intermediate lever.
 7. The apparatus according to claim 4, wherein the spray beam is fixedly mounted on the intermediate lever.
 8. The apparatus according to claim 5, wherein the rotation axis of the intermediate lever is located between the spray beam and the pivot axis of the additional actuator on the intermediate lever.
 9. The apparatus according to claim 8, wherein the actuators are designed for establishing defined displacement paths.
 10. The apparatus according to claim 9, wherein the actuators are hydraulic piston-cylinder assemblies.
 11. In combination with a roll rotatable about a roll axis in a roll frame, a cooling apparatus comprising: a lever pivotal on the roll frame about a lever axis extending parallel to the roll axis; a spray beam mounted on the lever offset from the lever axis and from the roll axis, extending along a beam axis generally parallel to and offset from the roll axis, and having nozzles directed from the beam axis at the roll; means for supplying a cooling medium through the beam to the nozzles for spraying the cooling medium on the roll; and means for pivoting the lever about the lever axis and thereby moving the spray beam radially of the roll axis. 